The present invention relates to diffusers, and in particular, to a wedge-type diffuser for use in gas turbine engines. In some gas turbine engines a diffuser is positioned downstream of a compressor impeller to receive compressed gas and reduce the flow velocity, thus converting kinetic energy of the compressed gas into static pressure. Such diffusers often have vanes for improving efficiency and reducing vortices. Using a vaned diffuser adds undesirable mass, and consequently weight, to the gas turbine engine. In applications where it is especially important to reduce weight, such as gas turbine engines used on aircraft, the additional mass of a vaned diffuser is especially undesirable.